This study provides the first maps of variations in
bacterial community structure on a broad scale based
on genotyping of DNA extracts from 593 soils from
four different regions of France (North, Brittany,
South-East and Landes). Soils were obtained from the
soil library of RMQS ("Réseau de Mesures de la
Qualité des Sols" = French soil quality monitoring
network). The relevance of a biogeographic approach
for studying bacterial communities was demonstrated
by the great variability in community structure
and specific geographical patterns within and
between the four regions. The data indicated that the
distribution of bacterial community composition
might be more related to local factors such as soil
type and land cover than to more global factors such
as climatic and geomorphologic characteristics.
Furthermore, the regional pools of biodiversity could
be ordered: South-East  North > Brittany > Landes,
according to the observed regional variability of the
bacterial communities, which could be helpful for
improving land use in accordance with soil biodiversity
management.